(Reuters) - The U.S. Food and Drug Administration's staff expressed concerns over the risk of incorrectly administering Collegium Pharmaceuticals Inc's long-acting opioid painkiller.

The experimental pill, to be called Xtampza, is designed to be taken after eating as data has shown the absorption of the opioid increases in the presence of food. (http://1.usa.gov/1MaT3GL)

Inadequate pain control caused by lack of food could lead to overdosing, reviewers said. Prescription opioid abuse has the potential to produce euphoric highs and disrupt the parts of the brain that control breathing.

Collegium has proposed to make clear on the label that Xtampza, an oral formulation of oxycodone, should only be taken after eating.

But reviewers argued that the packaging design would be "inadequate" in eliminating the risk of an administration error, noting that most oral opioid products can be given without respect to food intake.

The sole exception is Endo International Plc's Opana ER, which is taken on an empty stomach.

Reviewers said if the FDA eventually determines that Xtampza's benefits outweigh its risks, the company should assess the effectiveness of its packaging in preventing incorrect use.

The review was published on the FDA's website on Wednesday ahead of a meeting on Friday of a panel of outside advisers who will recommend whether the drug should be approved.

The FDA is not obliged to follow the advice of its advisory panels but typically does so.

Reviewers on Tuesday had also alluded to likely errors in administering Purdue Pharma's experimental fast-acting oxycodone painkiller as the drug is designed for use on an empty stomach.

(Refiles to correct spelling to "Collegium" from "Colleguim" in first paragraph)

(Reporting by Natalie Grover and Samantha Kareen Nair in Bengaluru; Editing by Saumyadeb Chakrabarty)